US20060152207A1 - Electrical connection system for an electrochemical analysis system - Google Patents

Abstract

The invention relates to an electrical connection system for an analysis system and a method for analysis of a liquid sample on an analytical test element using the described analysis system. The analysis system comprises an evaluation appliance for evaluation of electrical signals, a test element holder for holding and positioning of an analytical test element in a measurement position, and at least one electrical contact element configured to make electrical contact with at least one electrical contact surface of an analytical test element, and to produce an electrical connection between the contact surface and the evaluation appliance. The at least one contact element is arranged to move to contact the contact surface of a test element held either in a fixed test element holder or a moveable test element holder, such as a slide. Furthermore, the analysis system has a means for moving the electrical contact element to the electrical contact surface of an analytical test element when the test element holder is in the measurement position.

Description

REFERENCE TO RELATED APPLICATIONS
• The present application is based on German Patent Application No.DE 10 2004 060 322.7, filed Dec. 15, 2004 and European Patent Application No. EP 05022049.0, filed Oct. 10, 2005 which are hereby incorporated by reference in their entirety.
TECHNICAL FIELD
• The present invention relates to an electrochemical analysis system and more particularly to an electrical connection system and method for electrically connecting a test element and an electrochemical evaluation appliance of the analysis system.
BACKGROUND
• Analysis systems which allow individual parameters in sample liquids to be determined have been known for a long time, and many versions of them are commercially available. Particularly for the field of medical diagnosis and environmental analysis, appliances are offered which can also be operated by personnel with less training. Systems such as these which operate without the use of liquid reagents and in which, in general, no preparation of the sample material, or at least no complex preparation of the sample material, is required, are simple to operate. A “dry chemistry” has been developed for these so-called quick tests, in which the liquid contained in the sample liquid is used on its own as a solvent.
• By way of example, systems for determination of glucose in the blood are in use, in which the patient places a small amount of blood on a test element, and carries out the measurement using an appliance which is simple to operate.
• Conventional evaluation appliances have an opening, for example a slot, into which a test element can be inserted, typically by hand. Guide elements ensure that a test element is inserted in the intended orientation. The appliance typically has design features in order to ensure the desired positioning of the test element.
• There are various forms of test elements. Those known include, for example, substantially small rectangular sheets, which are also referred to as strips, in whose center a multilayer test area is located. Diagnostic test elements which are in the form of strips are also referred to as test strips. Capillary test elements are known from the prior art, for example from WO 99/29429, for three-dimensional separation of a detection zone and a sample application point on a test element.
• A large number of methods are known for measurement of the concentration of analytes, for example of glucose in a blood sample. Methods such as these are normally subdivided into one of two categories: optical methods or electrochemical methods.
• Optical methods are based on color changes which produce an indication in the course of the verification reaction when the analytes to be determined are present. The color change which occurs on the test element can be detected by reflection-photometry. A transmission measurement is likewise possible, but in some cases necessitates the use of transparent test strips.
• Electrochemical methods for determination of the concentration of an analyte are based, for example, on amperometry or coulometry. Methods such as these are known, for example, from the documents U.S. Pat. No. 4,654,197, EP 0 505 475 B1, US 2002/0057993 A1,EP 1 321 769 A1, WO 03/083469 A2 or U.S. Pat. No. 5,108,564. Electrical signals must be transmitted between the test element and the evaluation appliance in order to carry out the electrochemical analysis. A test element which has been introduced into an evaluation appliance therefore has to have electrical contact made with it in the evaluation appliance, with the aid of an electrical connection system.
• Test elements which are used in the prior art are generally designed in layers and have contact surfaces in the form of thin metallic or otherwise conductive layers, in order to make electrical contact. In the case of evaluation appliances which are commercially available at the moment, the electrical contact elements of the appliance slide over the contact surfaces during the insertion of the test element, and can damage it in the process. Furthermore, material accumulations occur at the electrical contact elements of the evaluation appliance. Reliable contact can therefore not be ensured.
SUMMARY
• One object of the present invention is thus to avoid the stated disadvantages of the prior art and to provide an analysis system having an electrical connection system for connecting an analytical test element to an evaluation appliance, and a method for electrical connection of a contact surface of a test element in an evaluation appliance, which allow reliable contact to be made between the test element and the evaluation appliance. A further aim is to avoid abrasive damage to the test element by the electrical contacts of the analysis system during insertion of the test element into a measurement position in the analysis system.
• According to the invention, this object is achieved by an analysis system for analysis of a liquid sample on an analytical test element, comprising an evaluation appliance for evaluation of electrical signals, a test element holder configured to hold and position an analytical test element in a measurement position within the analysis system, and at least one electrical contact element configured to make electrical contact with at least one electrical contact surface of an analytical test element provided in the test element holder to produce an electrical connection between the contact surface and the evaluation appliance, wherein the at least one contact element is arranged such that it can move relative to the test element holder, and wherein the analysis system has a means for moving the electrical contact element into contact with the electrical contact surface of the analytical test element when the test element is positioned in the measurement position in the test element holder.
• The object is also achieved by a method for analysis of a liquid sample on an analytical test element, including the steps of moving the analytical test element to a measurement position in a test element holder in an analysis system, and moving a contact element relative to the test element holder towards a contact surface of the test element in order to make electrical contact with the analytical test element and in order to produce an electrical connection between the contact surface and the evaluation appliance, and, using the evaluation appliance, evaluating an electrical signal which is transmitted from the test element via the contact surface and the contact element.
• The analysis system according to the invention may, for example, be an appliance for evaluation of glucose in a body fluid, in particular in the blood. The liquid sample to be analyzed is passed to the test element which, if appropriate, contains reagents which react with components of the sample. For analysis purposes, this test element is moved manually or automatically to a measurement position in the test element holder in the evaluation appliance, before or after the sample is taken. The measurement position is in this case that position of the test element in the analysis system in which the electrochemical analysis of the sample on the test element takes place.
• An electrical contact element makes contact with the test element when it is arranged in the measurement position for electrochemical analysis. For this purpose, the electrical contact element is moved towards a contact surface on the test element by the means for moving the electrical contact element, and contacts it, such as by pressing against it. At least when the test element is positioned in the measurement position, the contact element is in electrical communication with the evaluation appliance, for example with an electrochemical evaluation circuit configured to perform the analysis of the liquid sample based at least partially on the electrical signals transmitted from the test element. As a result, an electrical connection is produced between a test element in the measurement position and the evaluation appliance. Electrical signals are transmitted via this connection to the evaluation appliance, and are used to determine the glucose content or the content of some other electrochemically detectable analyte in the sample on the test element.
• By making electrical contact with the test element using the analysis system according to the invention, and by using the method according to the invention, the contact element does not touch the contact surface of the analytical test element until the test element is positioned in the measurement position. The separation of the positioning of the test element and the process of making contact with it helps to prevent the contact element from grinding or scratching the contact surface. The electrode structure of the test element is thus not damaged this way. Since virtually no friction takes place between the at least one contact element and the at least one contact surface, very small contact surfaces can be used, thus resulting in a high miniaturization potential. The analysis system according to the invention and the method according to the invention also result in less risk of contamination to the contact element by the sample during removal of the test element with the sample from the measurement position after analysis, since the contact element is separated from the test element again, before removal. When contact is being made with the test element, the electrical contact element does not press against the contact surface with a high contact force until after positioning in the measurement position, thus ensuring a reliable contact and, if appropriate, additional fixing of the test element by means of the contact element.
• According to one embodiment of the present invention, the contact element is moved at substantially right angles to the contact surface of an analytical test element which is held in the test element holder. This therefore avoids any parallel movement of the contact element with respect to the contact surface, and thus damage of the test element resulting from the contact element sliding over its surface. Furthermore, the contact element can be moved by a rotary movement towards the contact surface of an analytical test element which is held in the test element holder. The rotary movement is thus configured to result in substantially right angles as the contact element is in the vicinity of the contact surface.
• A clamping device may be arranged in a test element holder of the evaluation appliance such that the clamping device fixes a test element, which is to be positioned in the measurement position, in the test element holder.
• According to another embodiment of the present invention, a housing is provided for the analysis system generally or particularly for the evaluation appliance, with the test element holder and/or the means for moving the electrical contact element being arranged such that they or it can move relative to the housing. The contact element can be displaced by the means for moving the contact element either by the movement of the test element holder relative to the means for moving, or by movement of the means for moving relative to the housing (with the test element holder remaining fixed), so that the contact element is ultimately moved towards the test element as or after the test element is positioned in the measurement position. Electrical contact is thus made with the test element. The analysis system may also contain a drive for moving the test element holder and/or the means for moving the electrical contact element, or the test element holder and/or the means for moving the electrical contact element can be driven manually.
• The analysis system according to the invention may also contain a test element magazine for holding at least two test elements, and a test element removal device for automatic removal of a test element from the test element magazine and for transport of the test element to the measurement position in the test element holder. Various test element magazines are known from the prior art, for example as disclosed in DE 198 19 407 and DE 198 54 316 A1, each of which are hereby incorporated by reference herein. Examples of test element removal devices are disclosed in EP 0 738 666 B1, DE 197 15 031 A1, U.S. Pat. No. 5,575,403, DE 199 02 601 A1, and DE 43 26 339 A1, which are also hereby incorporated by reference herein.
• The invention also relates to an analysis system having an electrical connection system for connecting an analytical test element to an evaluation appliance, with the test element having at least one contact surface. The analysis system has a slide which can be moved between an initial position and an end position in a housing and contains a holding space with an inlet opening for holding the test element, with the holding space being bounded by a stop, and at least one contact element (possibly mounted on the slide), which is arranged such that, when the slide is in the initial position, it is at a distance from the contact surface of a test element which is held in the holding space, and such that it is moved from the initial position to the end position towards the contact surface by movement of the slide, and is pressed against the contact surface. The evaluation appliance according to the invention comprises an electrochemical evaluation circuit which is electrically connected to the contact element, at least in the end position of the slide. In this case, the slide is used as the test element holder. During movement of the slide, a means for moving the electrical contact element acts on the electrical contact element and moves it towards the contact surface.
• In one embodiment, the test element is pushed into the test element holder through the inlet opening into the holding space in the slide for analysis of a liquid sample on a test element, with the slide being located in its initial position. When using a test element in the form of a strip, by way of example, the inlet opening is in the form of an elongated slot. The holding space is a cavity which is formed in the slide and into which the test element can be inserted until it reaches the stop. When the slide is in the initial position, a contact element which is mounted on it is at a distance from the contact surface of the test element. When the test element is pushed into the slide, the contact element does not touch the test element.
• As soon as the test element has been inserted into the slide as far as the stop, the slide is moved away from the initial position to the end position, by means of the force which is still maintained in the insertion direction. The test element can be clamped in the holding space during the movement of the slide from the initial position to the end position, thus preventing any change in its position relative to the slide. By way of example, the end position of the slide may be defined by a further stop, which limits the movement of the slide. The movement of the slide from the initial position to the end position results in the contact element being moved towards the contact surface and being pressed against the contact surface, this resulting in electrical contact with the test element.
• During the movement of the slide from its initial position to its end position, the test element does not move in the slide with respect to the slide and the contact element. It remains arranged in the same position in the holding space in the slide, resting on the stop. Electrical contact is thus made when the contact element, which is pressed against the test element, is moved with the slide, thereby avoiding the test element sliding over the contact element resulting in damage to the test element or accumulation of material on the contact element.
• The sample which is located on the test element can be analyzed electrochemically in the end position, which thus comprises the measurement position. The electrochemical evaluation circuit is used for this purpose, and is electrically connected to the contact element, at least when the slide is in the end position. This electrical connection can be produced by the movement of the slide to the end position. However, the evaluation circuit can also be continuously electrically connected to the contact element.
• The electrochemical evaluation circuit is used, for example, for evaluation of measured electrical signals which depend on the concentration of an analyte on the test element with which contact is made. Electrochemical evaluation circuits such as these are known from the prior art, for example from EP-B1 0505475 or from U.S. Pat. No. 5,108,564, which are hereby incorporated by reference herein.
• In another embodiment of the present invention, the contact element is arranged recessed in a depression in the slide when the slide is in the initial position. The recessing of the contact element results in it being at a distance from the contact surface of the test element when the slide is in the initial position (in particular during insertion of the test element into the holding space).
• A clamping device may be arranged in the holding space of the slide, such that it fixes a test element, which has been inserted into the slide as far as the stop, in the holding space.
• The contact element in one embodiment extends through an opening in the slide, thereby reaching from the holding space within the slide to the outside of the slide. The contact element is then arranged such that it interacts with a contact-pressure element on the outside of the slide. In further embodiments, the contact-pressure element has a guide surface which is arranged such that it pushes the contact element into the holding space, towards the contact surface of a test element contained in it while the slide is being moved from its initial position to its end position. During the movement of the slide from the initial position to the end position, the guide surface of the contact-pressure element which is arranged outside the slide drives the contact element, which extends through the opening to the outside of the slide, such that it is pressed into the holding space within the slide until a contact is made with the contact surface of the test element. In one embodiment, the guide surface is inclined in the direction of insertion and can have a curved surface or comprise a substantially flat plane.
• The electrical connections of the electrochemical evaluation circuit in the evaluation appliance can be connected directly to the contact element. However, they can also be connected to the contact-pressure element, which must then be electrically conductive, in order to achieve electrical contact with the contact surface of the test element upon interaction with the contact element.
• In another embodiment of the present invention, the contact-pressure element is resiliently flexible and is resiliently deformed when the slide is in the end position, such that it presses the contact element against the contact surface of the test element with an additional force. Resilient deformation which is produced by the pressure put on the contact-pressure element, for example by the bending of the flexible contact-pressure element, results in the contact element being subjected to a force in the opposite direction to the deforming force, pressing the contact element against the contact surface of the test element.
• In yet other embodiments, the contact element itself is resiliently flexible. The contact element is then deformed resiliently, such as by pressure applied by the contact-pressure element, such that it presses against the contact surface with a force (which if appropriate opposes the deforming force).
• The invention also relates to an electrical connection system in an analysis system. The electrical connection system has a slide which can be moved between an initial position and an end position in a housing and contains a holding space with an inlet opening for holding a test element having at least one contact surface, with the holding space being bounded at least by a stop. The electrical connection system also has at least one contact element, which is arranged such that, when the slide is in the initial position, it is at a distance from the contact surface of a test element which is held in the holding space, and such that it is moved from the initial position to the end position towards the contact surface by movement of the slide, and is pressed against the contact surface.
• The invention also relates to an analysis system for analysis of an analyte in a liquid sample, comprising an evaluation appliance which contains at least one electrical connection system according to the invention. The analysis system may also comprise a device for removal of body fluid from a body part. A large number of body fluid removal devices are known from the prior art, for example from WO 01/89383. These are used, for example, to obtain venous blood from the finger tips, or blood or interstitial fluid from other body parts. The body fluid obtained in this way is applied to the test element in order to be analyzed by the analysis system, for example for evaluating its glucose content.
• In yet other embodiments, the analysis system may have a supply container for test elements and a removal apparatus for automatic removal of at least one test element from the supply container. The analysis system according to this embodiment is an integrated system, by means of which the taking of a sample (for example perforation of the skin and application of blood to a test element which has been taken from a supply container, has been transported to the sample taking position and has been positioned there) and sample analysis (for example transport and positioning of the test element with the sample in the measurement position, measurement and evaluation of the relevant variables, indication of the analysis result) are carried out automatically.
• The invention also relates to an analysis system for analysis of a liquid sample on a test element, comprising a housing, an evaluation appliance for evaluation of electrical signals and at least one electrical contact element which is used to make electrical contact with at least one electrical contact surface of an analytical test element for enabling an electrical connection to the evaluation appliance. The evaluation appliance according to the invention also includes a test element holder which is arranged firmly relative to the housing of the analysis system. The test element holder thus cannot be moved relative to the housing. In the analysis system according to this embodiment, the at least one contact element is arranged such that it can move relative to the test element holder. The analysis system also has means for moving the electrical contact element to the electrical contact surface of an analytical test element when it is positioned in the measurement position in the test element holder.
• Also in this embodiment, the means for moving the electrical contact element is moved manually or automatically (for example by means of an electric motor) in order to operate the electrical contact element so that it is moved to the contact surface of the test element.
• According to another embodiment of the present invention, the analysis system has a test element magazine for at least two test elements, and a test element removal device for removal of test elements from the test element magazine, with the test element removal device having a drive by means of which the means for moving the electrical contact element can also be moved. For example, in the already described removal device from the prior art with a plunger, the plunger is driven via a coupling to a threaded rod which is rotated by an electric motor. In the analysis system according to the invention, the means for moving the contact element may, for example, likewise be moved via a coupling to this threaded rod by means of the electric motor of the removal device. In this case, the means for moving the electrical contact element can be a rod which can be moved substantially in the longitudinal direction and has a rod end by means of which the electrical contact element, which is in the form of an electrical toggle lever, can be moved to the contact surface of a test element which is positioned in the measurement position in the test element holder. The toggle lever is in this case preloaded by a spring element such that it is located in a position away from the test element holder until it is operated by the rod end. During test element removal from the test element magazine, the rod is moved parallel to the plunger, and the rod end reaches and operates the toggle lever only when the test element that has been removed has reached the measurement position in the test element holder. The rod end then tilts the toggle lever, which is provided as the contact element, so that it makes electrical contact with the test element, and makes an electrical connection to the evaluation appliance.
• The statements which have been made above with reference to the electrical connection system according to the invention and the analysis system according to the invention apply (to the extent that they are applicable) in the same way to the method according to the invention.
• The invention also relates to a method for electrical connection of a contact surface of a test element in an analysis system, having the following steps: inserting the test element into a holding space as far as a stop in a slide which is arranged in a housing such that it can be moved between an initial position and an end position, with the slide being located in the initial position, and a contact element connected to the slide being at a distance from the contact surface of the test element when the slide is in the initial position, and moving the slide with the test element contained in it from the initial position to the end position, with the contact element being moved towards the contact surface of the test element as a result of such moving, and being pressed against the contact surface when the slide is in the end position.
• The invention also relates to a method for analysis of a liquid sample on an analytical test element, including the following steps: moving the analytical test element to a measurement position in a test element holder in an evaluation appliance, and moving a contact element relative to the test element holder towards a contact surface of the test element which is arranged in the measurement position, in order to make electrical contact with the analytical test element and in order to produce an electrical connection to the evaluation appliance, and using the evaluation appliance, evaluating an electrical signal which is transmitted from the test element via the contact surface and the contact element, by the evaluation appliance, wherein the analytical test element is moved to the measurement position in a test element holder which is arranged to be fixed relative to a housing of the evaluation appliance.
• These and other features and advantages of the present invention will be more fully understood from the following detailed description of the invention taken together with the accompanying claims. It is noted that the scope of the claims is definitely by the recitations therein and not by the specific discussion of the features and advantages set forth in the present description.
BRIEF DESCRIPTION OF THE DRAWINGS
• The following detailed description of the embodiments of the present invention can be best understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals and in which:
• FIG. 1 shows a schematic illustration of one embodiment of an electrical connection system, which is contained in an analysis system according to the present invention, for a test element;
• FIGS. 2A to2C show three steps in the process of making contact with a test element in an electrical connection system as shown inFIG. 1;
• FIG. 3 shows a schematic illustration of a second embodiment of an electrical connection system for an analysis system according to the present invention, and the process of making contact with a test element contained in it;
• FIG. 4 shows a schematic illustration of a third embodiment of an electrical connection system for an analysis system according to the present invention, and the process of making contact with a test element contained in it;
• FIG. 5 shows a schematic illustration of a fourth embodiment of an electrical connection system for an analysis system according to the present invention, and the process of making contact with a test element contained in it;
• FIG. 6A shows a fifth embodiment of an analysis system according to the present invention; and
• FIG. 6B shows a plan view of the analysis system shown inFIG. 6A.
• Skilled artisans appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help improve understanding of the embodiment(s) of the present invention.
• In order that the invention may be more readily understood, reference is made to the following description of embodiments of the invention, which are intended to illustrate the invention, but not limit the scope thereof.
DETAILED DESCRIPTION
• The following description of the preferred embodiment is merely exemplary in nature and is in no way intended to limit the invention or its application or uses.
• FIG. 1 shows one particular embodiment of an electrical connection system which is contained in an analysis system according to the present invention, for electrical connection of atest element6 to anevaluation appliance55.
• Aslide2, such as a test element holder23 (an example of which is shown inFIG. 6A), is arranged in ahousing1. Theslide2 can be moved in thehousing1, in the movement direction indicated by the double-headedarrow3. Anelectrical contact element4 is mounted on theslide2 and is also moved in themovement direction3 during movement of theslide2. Theslide2 is illustrated in its initial position inFIG. 1. Theslide2 defines a holdingspace5 for holding atest element6. The holdingspace5 extends in theslide2 from the inlet opening7 (which is exemplified in the form of a slot for purposes of receiving a strip-type test element) as far as astop8. Thetest element6 is inserted into the holdingspace5 as far as thestop8 through theopening7 with theslide2 in the initial position. When theslide2 is in the initial position, thecontact element4 is arranged recessed with respect to thetest element6, in adepression9 in the holdingspace5. In the initial position, thecontact element4 is thus at a distance from thetest element6, and does not touch it. Thetest element6 has (on itslower face10 inFIG. 1) at least one contact surface16 (shown inFIGS. 3-5), which is arranged directly opposite thecontact element4 when thetest element6 has been inserted into the holdingspace5 in theslide2 as far as thestop8.
• Thecontact element4 extends through and is moveably maintained within anopening11 in theslide2. A contact-pressure element12 is provided on the outside of theslide2, as themeans24 for moving the contact element, and interacts with thecontact element4, as will be explained in more detail in the following text with reference toFIGS. 2A to2C.
• FIGS. 2A to2C show three steps in the process of making contact with the at least one contact surface of a test element in the electrical connection system shown inFIG. 1.
• FIG. 2A shows theslide2 in the initial position in thehousing1. Theslide2 is in this case located against afirst stop13 in thehousing1. Thecontact element4 is arranged recessed in thedepression9 in the holdingspace5. Atest element6 is inserted into the holdingspace5 through theinlet opening7 until it meets thestop8. During this process, theslide2 remains in its initial position. The separated (recessed) arrangement of thecontact element4 in the holdingspace5 prevents thetest element6 from sliding over thecontact element4 during insertion into the holdingspace5, and prevents damage to thetest element6 or contamination of thecontact element4, as may occur during this process in conventional connection systems. Furthermore, thecontact element4 extends through and is moveably maintained within theopening11 in theslide2 to the outside, but is at a distance from the contact-pressure element12.
• FIG. 2B shows theslide2 in a position in thehousing1, which is between the initial position and the end position. Once thetest element6 has been inserted, as is shown inFIG. 2A, as far as thestop8 into theslide2, theslide2 is moved to its end position together with thetest element6 in the insertion direction by a continuous manually or automatically applied force. During this process, thecontact element4 interacts with the contact-pressure element12 in such a way that, as soon as it reaches the contact-pressure element12, it slides over aguide surface14, which is in the form of a incline, on the contact-pressure element12 and is resultingly displaced through theopening11 into the holdingspace5 to the contact surface of thetest element6. Thecontact element4 is moved at substantially right angles to the contact surface during this process. In contrast, no relative movement of thecontact element4 parallel to the surface of thetest element6, which could result in damage to the surface, is produced, by virtue of the mounting of thecontact element4 in theslide2. During insertion of theslide2, thetest element6 can be fixed by means of a clamping device (not illustrated) in the holdingspace5 such that it rests on thestop8, so that it does not move therein during insertion of theslide2.
• FIG. 2C shows theslide2 in the end position in thehousing1. The end position is defined by asecond stop15 for theslide2 in thehousing1, and represents the measurement position for the test element, which rests on thestop8 in the holdingspace5 in theslide2. Thecontact element4 is pressed against the contact surface on thelower face10 of thetest element6, so that an electrical contact is produced. The contact-pressure element12 is composed of a resiliently flexible material. It is thus bent downward by thecontact element4, which presses against thecontact surface16 of thetest element6, in the end position as illustrated inFIG. 2C, so that it exerts a corresponding opposing force on thecontact element4 upward (against the contact surface16).
• Once the analysis of the sample has been carried out with the aid of an electrochemical evaluation circuit (not illustrated), which is located in theevaluation appliance55, thetest element6 is pulled in the direction of the initial position of theslide2. In consequence, theslide2 is moved together with thetest element6, which is fixed in it, as far as itsfirst stop13, and thetest element6 is then moved to itsfirst stop13, and thetest element6 is then pulled out of its holdingspace5, with thecontact element4 once again being recessed with respect to thetest element6 in thedepression9, as inFIG. 2A. The electrical connection system is once again located in its initial position, ready for the next contact-making process.
• FIG. 3 shows a schematic illustration of a second embodiment of an electrical connection system in an analysis system according to the present invention, for electrical connection of atest element6 to anevaluation appliance55.
• The electrical connection system has ahousing1 in which a slide2 (test element holder23) can be moved between an initial position (FIG. 3, top) and an end position (FIG. 3, bottom). Theslide2 contains a holdingspace5 with aninlet opening7, in which atest element6 is held inFIG. 3. The holdingspace5 is bounded by astop8. The electrical connection system illustrated inFIG. 3 also has anelectrical contact element4, which is at a distance from thecontact surface16 of thetest element6 when theslide2 is in the initial position (FIG. 3, top). In the initial position, theslide2 rests on afirst stop13. Thecontact element4 has a plurality of bends and is attached to thehousing1 at one end (and ultimately to an electrochemical evaluation circuit, now shown), and to theslide2 at the other end. During manual or automatic movement of theslide2 with atest element6 contained in it from the initial position (FIG. 3, top) to the end position (FIG. 3, bottom), thecontact element4 is resiliently deformed. The resilient deformation is produced by that end of thecontact element4 which is attached to theslide2 being moved together with theslide2 relative to thehousing1, while the position of that end which is attached to thehousing1 does not change. As a result of the resilient deformation of thecontact element4, asub area17 of thecontact element4 which is arranged close to thecontact surface16 of thetest element6 is moved towards thecontact surface16 and is pressed against thecontact surface16 in the end position of theslide2, thus producing an electrical contact in the measurement position. Theslide2 is thus itself used as themeans24 for moving thecontact element4. In the end position (FIG. 3, bottom), theslide2 rests on asecond stop15. During movement of theslide2 from the end position back to the initial position, the movement of thecontact element4 is reversed, and the electrical contact is disconnected again.
• FIG. 4 shows a third embodiment of an electrical connection system in an analysis system according to the invention, for electrical connection of atest element6 to anevaluation appliance55.
• The electrical connection system comprises ahousing1 and aslide2 that can be moved between an initial position (FIG. 4, top) and an end position (FIG. 4, bottom) (movement direction3). During this process, theslide2 is moved from afirst stop13 to asecond stop15. Atest element6 is arranged in a holdingspace5 with aninlet opening7 and astop8. Anelectrical contact element4, which is mounted such that it can rotate about anaxis18, is mounted on theslide2. Thetest element6 has acontact surface16. Oneend19 of thecontact element4 strikes anelectrical contact20 when theslide2 is in the end position. Theelectrical contact20 is used as themeans24 for moving the contact element, and presses against theend19 which is configured such that thecontact element4 is resultingly moved, by a rotary movement about theaxis18 which causes movement of itsother end21, towards thecontact surface16 of thetest element6, which is held in the measurement position in the slide, and makes electrical contact with it. The electrical contact then exists between thecontact surface16 of thetest element6, thecontact element4 and thecontact20 which, for example, is connected to theelectrical cables22 of an electrochemical evaluation circuit (not illustrated) in theevaluation appliance55.
• FIG. 5 shows a fourth embodiment of an electrical connection system in an analysis system according to the invention, for electrical connection of atest element6 to anevaluation appliance55.
• Aslide2 is arranged in ahousing1 and can be moved between an initial position (FIG. 5, top) and an end position (FIG. 5, bottom) between twostops13,15. Theslide2 contains atest element6 in a holdingspace5, which has aninlet opening7 and astop8. Acontact element4 is fixedly connected to theslide2, and is set at a distance from thecontact surface16 of thetest element6 in the initial position. During movement of theslide2 to the end position (FIG. 5, bottom), thecontact element4 slides along a contact-pressure element12, which is connected to thehousing1. As a result, thecontact element4 is resiliently deformed such that itsfirst end21 is moved towards thecontact surface16 of thetest element6, and is pressed against thecontact surface16 in the end position by means of the contact-pressure element12, which is provided as themeans24 for moving the contact element, so that an electrical contact is produced. When theslide2 is in the end position, oneend19 of thecontact element4, which projects beyond theslide2, rests on anelectrical contact20. The electrical contact then exists between thecontact surface16 of thetest element6, thecontact element4 and thecontact20 which, for example, is connected toelectrical cables22 of an electrochemical evaluation circuit (not illustrated) in theevaluation appliance55.
• FIG. 6A shows a fifth embodiment of an analysis system50 according to the invention.
• Thetest element holder23 in the analysis system is located under anelectrical contact element4, which is in the form of a toggle lever25 and is used to make electrical contact with at least one electrical contact surface of ananalytical test element6, and in order to produce an electrical connection to an evaluation appliance (not shown inFIG. 6A) which is included in the analysis system. Thecontact element4 is arranged such that it can move relative to thetest element holder23. Thecontact element4 can be moved by a rotary movement about arotation axis26 towards the contact surface of a test element which is arranged in the measurement position in thetest element holder23.
• Thetest element holder23 is arranged such that it is fixed relative to thehousing1, and is fixed to it by means ofscrews27. A rod29, which can be moved substantially in thelongitudinal direction28 with respect to thehousing1 and with respect to thetest element holder23, is provided as themeans24 for moving theelectrical contact element4 and itsrod end30 can operate the toggle lever25 in order to move thecontact element4 onto the contact surface of a test element which is arranged in the measurement position. The toggle lever25 is held by aspring element31 in the illustrated initial position, in which it is at a distance from thetest element holder23, for as long as it is not moved by therod end30 against the spring force of thespring element31 towards thetest element holder23.
• In the analysis system according to the invention as illustrated inFIG. 6A, themeans24 for movement of theelectrical contact element4 is moved automatically by a drive (not illustrated). The drive comprises an electric motor, which drives a testelement removal device32 for automatic removal of a test element from atest element magazine33. Thetest element magazine33 comprises a container in the form of a drum, which can hold a large number of test elements in individually sealedchambers34. The testelement removal device32 contains aplunger35. Thisplunger35 is coupled to a threadedrod37 via atransmission element36. The threadedrod37 is rotated by the drive (not illustrated) during operation of the testelement removal device32. Thetransmission element36 converts this rotary movement of the threadedrod37 to a linear movement in thelongitudinal direction28. In consequence, theplunger35 is likewise moved in thelongitudinal direction28. In order to remove a test element from thetest element magazine33, it is rotated to a position in which thechamber34 which contains the test element to be removed is arranged in front of thetest element holder23. Theplunger35 is then moved linearly in thelongitudinal direction28, breaks through the seal on thechamber34, and pushes the test element out of thechamber34 into thetest element holder23.
• The rod29 is likewise moved in the longitudinal direction parallel to theplunger35, since it is also coupled to the threadedrod37, via thetransmission element36. As soon as theplunger35 has pushed the test element that has been removed from thetest element magazine33 and is in thetest element holder23 into the measurement position, therod end30 reaches the toggle lever25 and tilts this towards the test element, so that thecontact element4 makes contact with the contact surface of the test element. In this position, thecontact element4 produces an electrical connection between the test element and the evaluation appliance (not illustrated in FIGS.6A-B), thus allowing an electrochemical analysis to be carried out on a sample on the test element.
• FIG. 6B shows a plan view of the analysis system shown inFIG. 6A.
• This plan view illustrates, in particular, the electrical contact element4 (toggle lever25), themeans24 for moving the contact element4 (rod29 with the rod end30), the threadedrod37, thetransmission element36, theplunger35, thetest element magazine33, thehousing1 and thescrews27.
• It is noted that terms like “preferably”, “commonly”, and “typically” are not utilized herein to limit the scope of the claimed invention or to imply that certain features are critical, essential, or even important to the structure or function of the claimed invention. Rather, these terms are merely intended to highlight alternative or additional features that may or may not be utilized in a particular embodiment of the present invention.
• For the purposes of describing and defining the present invention it is noted that the term “substantially” is utilized herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. The term “substantially” is also utilized herein to represent the degree by which a quantitative representation may very from a stated reference without resulting in a change in the basic function of the subject matter at issue.
• Having described the invention in detail and by reference to specific embodiments thereof, it will be apparent that modification and variations are possible without departing from the scope of the invention defined in the appended claims. More specifically, although some aspects of the present invention may be identified herein as preferred or particularly advantageous, it is contemplated that the present invention is not necessarily limed to these preferred aspects of the invention.

Claims (22)

1. An analysis system for analysis of a liquid sample on an analytical test element, comprising an evaluation appliance for evaluation of electrical signals, a test element holder configured to hold and position an analytical test element in a measurement position within the analysis system, and at least one electrical contact element configured to make electrical contact with at least one electrical contact surface of an analytical test element provided in the test element holder to produce an electrical connection between the contact surface and the evaluation appliance, wherein the at least one contact element is arranged such that it can move relative to the test element holder, and wherein the analysis system has a means for moving the electrical contact element into contact with the contact surface when the test element is positioned in the measurement position in the test element holder.

2. The analysis system ofclaim 1, wherein the contact element is moveable at substantially right angles to the contact surface.

3. The analysis system ofclaim 2, wherein the means for moving the contact element comprises rotary movement of the contact element towards the contact surface.

4. The analysis system ofclaim 1, further comprising a housing, the test element holder and the contact element being provided in said housing, and the test element holder being moveable relative to the housing.

5. The analysis system ofclaim 4, the test element holder and the contact element comprising an electrical connection system for producing an electrical connection between the evaluation appliance and a test element held within the test element holder, the test element holder comprising a slide that is moveable between an initial position and an end position within the housing, the end position comprising the measurement position, the slide defining a holding space bounded by a stop and configured to receive a test element through an inlet opening in the slide, wherein the electrical connection system is configured such that the contact element is set at a distance from the contact surface of the test element when the test element is held in the holding space and the slide is in the initial position, and such that the means for moving the contact element causes the contact element to be pressed against the contact surface when the slide is in the end position in order to produce and electrical connection between the contact surface and the evaluation appliance.

6. The analysis system ofclaim 5, the contact element being at least partially mounted on the slide.

7. The analysis system ofclaim 6, the contact element being mounted on the slide and recessed relative to the test element in a depression in the holding space when the slide is in the initial position.

8. The analysis system ofclaim 7, the contact element extending through and being moveably maintained within an opening in the slide, the means for moving the contact element comprising a contact-pressure element fixedly mounted within the housing and outside the slide.

9. The analysis system ofclaim 8, the contact-pressure element having a guide surface configured to displace the contact element into the holding space toward the contact surface as the slide is moved from the initial position to the end position.

10. The analysis system ofclaim 9, the contact-pressure element comprising an inclined plane configured to guide the contact element as the slide is moved from the initial position to the end position.

11. The analysis system ofclaim 8, the contact-pressure element comprising an electrically conductive material and being in electrical communication with the evaluation appliance.

12. The analysis system ofclaim 6, the contact element also being partially fixedly mounted on the housing and being resiliently flexible and configured such that movement of the slide from the initial position to the end position resiliently deforms the contact element into contact with the contact surface.

13. The analysis system ofclaim 6, the contact element also being resiliently flexible and comprising one end that contacts an electrical contact in electrical communication with the evaluation appliance when the slide is in the end position, and an other end that is resiliently deformed toward the contact surface when the slide is in the end position by a contact-pressure element fixedly mounted to the housing, the contact-pressure element comprising the means for moving the contact element.

14. The analysis system ofclaim 6, the contact element being rotatably mounted to the slide, the means for moving the contact element comprising an electrical contact in electrical communication with the evaluation appliance, the contact element comprising one end that contacts the electrical contact when the slide is in the end position and which contacting causes an other end of the contact element to rotate towards the contact surface.

15. The analysis system ofclaim 1, further comprising a housing, the test element holder and the contact element being provided with the housing, and the test element holder being fixed relative to the housing.

16. The analysis system ofclaim 15, further comprising a test element magazine for holding at least two test elements, and a test element removal device for removal of a test element from the test element magazine and for transport of the test element to the measurement position in the test element holder.

17. The analysis system ofclaim 16, the test element removal device comprising a drive operatively connected to the means for movement of the contact element.

18. The analysis system ofclaim 16, wherein the contact element comprises a toggle lever, and the means for moving the contact element comprises a rod moveable in the substantially longitudinal direction and having a rod end by means of which the contact element can be moved to the contact surface of a test element which is positioned in the measurement position in the test element holder.

19. The analysis system ofclaim 1, wherein the evaluation appliance comprises an electrochemical evaluation circuit configured to perform analysis of the liquid sample on the test element based at least partially on the electrical signals transmitted from the test element.

20. A method for analysis of a liquid sample on an analytical test element, comprising the steps of: moving the analytical test element to a measurement position in a test element holder in an analysis system; moving a contact element relative to the test element holder towards a contact surface of the test element in order to make electrical contact with the analytical test element and in order to produce an electrical connection between the contact surface and an evaluation appliance; and, using the evaluation appliance, evaluating an electrical signal which is transmitted from the test element via the contact surface and the contact element.

21. The method ofclaim 20, wherein the test element holder is fixed relative to a housing for containing the analysis system.

22. A method for electrical connection of a contact surface of a test element in an evaluation appliance for an analysis system, comprising the steps of: inserting the test element into a holding space as far as a stop in a slide which is arranged in a housing, the slide being moveable between an initial position and an end position, the slide being located in the initial position at the inserting step and a contact element being provided in the evaluation appliance and set at a distance from the contact surface when the slide is in the initial position; and moving the slide with the test element contained in it from the initial position into the end position, with the contact element being moved towards the contact surface of the test element and pressed against the contact surface when the slide is moved into the end position.

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